SIEMENS
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Siemens D 11 · 2015
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Function
(continued)
2
Highlights
Safety Integrated
Safely Limited Position (SLP)
The SLP function monitors the axis to ensure that it remains
within the permissible traversing range.
Activation
When SLP is activated, the traversing range limited by the con-
figured software limit switches is safely monitored. If the permit-
ted traversing range is exited, a customizable fault reaction oc-
curs. It is possible to toggle between two traversing ranges,
even when the machine is in operation.
Application
SLP is used for applications in which machine operators have to
enter a protection area, e.g. for feeding in and removing mate-
rial. Safe monitoring of the axis position ensures that the axis
cannot move into the protection area released for operators and
so place them in danger, for example, on storage and retrieval
machines, gantry cranes or machining centers.
Customer benefits
SLP can be used for highly-effective protection area monitoring.
The function does away with the use of external components
such as hardware limit switches and the associated wiring ex-
pense. Due to the short reaction time following a limit overshoot,
safety clearances can be reduced.
Safe Position (SP)
The SP function transfers the actual position values determined
safely in the drive over safe PROFIsafe communication to a
safety control.
Activation
In contrast to the SLP function that monitors the current actual
position value against a limit and, in the case of an overshoot,
activates a drive-integrated fault reaction, SP transfers the cur-
rent actual position values to the safety control. Position monitor-
ing is implemented in the safety program of the control. Ex-
tended PROFIsafe telegrams are available for transferring the
position values. The position values can be transferred in 16-bit
or 32-bit resolution, as required. A time stamp is also transferred
with the position values.
Application
Tailor-made safety concepts can be created using the SP func-
tion. It is ideal for use on machines that require flexible safety
functions. It is extremely versatile and can be used, for example,
to implement safe, axis-specific range detection by means of the
Safe Cams (SCA) function. The SP function can also be used to
implement multi-axis safety concepts, multi-dimensional protec-
tion areas and zone concepts.
Customer benefits
Position monitoring or speed monitoring is implemented in the
safety program of the control, so the user has the flexibility for im-
plementing tailor-made safety functions. The reaction to a limit
overshoot must also be specified in the safety program. This
means a higher initial programming outlay, but it does offer the
opportunity for initiating different fault reactions.
SLP
s
t
G_D211_XX_00310
SP
G_D211_XX_00309
© Siemens AG 2015